Hitherto, for a patient with a respiratory disease, a breathing gas supplying apparatus (hereinafter also referred to as an oxygen concentrating apparatus) for obtaining an oxygen-enriched gas by separating and concentrating atmospheric oxygen has been developed, and an oxygen therapy using the same has gradually become popular.
Although there is a case where the oxygen therapy is performed while the patient enters a medical institution, in the case where the respiratory disease of the patient becomes chronic, and it is necessary that the oxygen therapy is performed over a long period of time to calm and stabilize the symptom, a medical treatment is also performed in which the oxygen concentrating apparatus is installed in the patient's home, the oxygen-enriched gas supplied by this oxygen concentrating apparatus is guided to the vicinity of the nasal cavity of the patient by using a tube member called a cannula, and the patient inhales it. This kind of medical treatment is especially called a domiciliary oxygen therapy or HOT (Home Oxygen Therapy).
Since the home oxygen therapy was covered by insurance in 1985 in Japan, this has been prescribed mainly for the chronic obstructive pulmonary disease (COPD) and tuberculosis sequela, and the rough number of patients is 60 to 65 per hundred thousand persons in Japan and there are about eighty thousand persons (as of 2000). The old Welfare Ministry respiratory failure section and the like report that this home oxygen therapy improves the vital prognosis of the patient. It is inferred that the reason why the home oxygen therapy is effective is that the pulmonary circulation dynamics is improved with the improvement of anoxemia.
The home oxygen therapy is performed in steps of (1) doctor's medical examination of a patient, (2) doctor's issuance of a home oxygen therapy execution written directive describing a prescription to the patient based on the medical examination, (3) installation of an oxygen concentrating apparatus in a patient's home based on the written directive, (4) continuous execution of inhalation of an oxygen-enriched gas using the oxygen concentrating apparatus, and (5) medical examination at the time of a hospital visit which is made regularly, for example, once a month.